1. Field of the invention
The invention concerns a triplicated clock distribution device for use when each clock signal comprises a synchronization signal for distributing three clock and synchronization signals from three clocks to user units each comprising a receiver which receives on an AND-OR majority logic circuit the signals each carried by one transmission channel and separates the synchronization signal from the clock signal before these signals are delivered to the user units.
2. Description of the prior art
Such distribution devices are used whenever great stability is required of the clock signal together with great security of operation, as is the case in telephone exchanges, for example.
There exist distribution devices in which each clock signal comprises a synchronization signal consisting in the absence of a clock pulse.
Simulating the synchronization signal by means of the absence of a pulse in the clock signal produces a relatively significant error, in the order of 12%, in the cyclic ratio of the clock signal regenerated in the receivers at the time of the synchronization mark.
An object of the present invention is to achieve an error in the cyclic ratio of the regenerated clock signal at the time of the synchronization mark which is smaller than that given by simulating a synchronization signal by means of the absence of a pulse in the clock signal.